I have a friend who is imo in an abusive relationship. Her P deprives her of money, doesn't lift a finger in the house at all, not even to make a cup of tea ever, she doesn't trust him with their DC because he has zero patience, and she really struggles to keep everything going.
She does all of the childcare, housework, cooking, cleaning, organising, everything. Her P works f/t and then spends the rest of his time playing computer games with his brother/surfing the net. (My friend is banned from using the net btw.) When he isn't doing those he is sleeping, sometimes for the whole day.
Now, whilst it is frustrating to watch her struggling and see the effect this relationship is having on their DC, she refuses to contemplate a life without him because she says he is a good man
and he is not perfect but he is the same as other men. 
She talks about him alot, and brings him into every conversation, and I honestly don't think she can see how bad he really is. She criticises other people's partners when her own is awful. I have learnt to say nothing, because she gets defensive (I understand that.) and nothing changes so there seems little point until she accepts she deserves more IYSWIM.
Anyhow, her P lets her down alot, he wont take her shopping (she doesn't drive) and he sometimes disappears to his brothers all weekend from friday night to sunday evening to play computer games, leaving her with no gas (meter) and no electric (meter) and no money.
(He also takes the modem when he goes to work/his brothers so she can't go online for anything.)
She tells me all this and then says 'Ahhhh bless him, he worries' It is very frustrating to sit back and do nothing but that is the situation.
Anyhow, I am getting increasingly frustrated that while her P is playing computer games, or sleeping, my friend is asking her friends (including me) to take her shopping, because P is sleeping..bless him, or nip to the shop with her gas key (a bus ride away) and lend her a fiver to put some gas on, because her P hasn't left her with enough, or pick her DC up from nursery/school because her P has just phoned to say he wont be picking them up because he has gone to his brothers/is sleeping etc.
Only this last week, one of her DC was feeling quite poorly, and she needed to take this DC to the OOH Dr's (weekend) so she phoned her P but guess what? He was at his brother's and was in the middle of the next level on the computer game and couldn't just leave the game at that point, he needed to get to a save point first and he couldn't do that in time to drive back and take her to the Dr's. 
So she phoned me and I took them. On the way, she was very open about telling me that she'd told P not to worry, that she'd get a friend to help her out again and he wasn't to worry, she would cook his dinner for when he came home.
I feel that by helping her I am enabling him to continue not to bother. I don't want to see her suffer and her P knows this, he knows that she will find someone else to help her and the DC, but tbh, I am getting really frustrated by it now..it is every 2/3 days she needs another favour because her P has let her down again.
I am a shit friend, I know. I must be because I'm not happy about changing my plans at a moments notice to sit down a OOH Dr's surgery for 2.5 hours waiting for one of her DC to be seen, whilst watching the other DC when she went in to Gp with ill DC, because her P can't be fucking arsed and she can't see what's wrong with that!!
I must be a shit friend because I don't want to spend one day every week taking her shopping because her DP is fucking sleeping (after sleeping all night too) or surfing the net, or quite often because he just doesn't want to take her shopping..because he hates shopping (unless it involves power tools.) He has said this in front of me and other friends, so it is not just my friends version.
AIBU to think it's not my responsibility to pick up where her P is slacking and then have to listen to how bloody wonderful he is because she has to mention him in every single conversation, I kid you not??